Some existing positioning systems such as global positioning systems (GPS) determine the location of devices using satellites. Other systems such as collaborative positioning systems determine the location of the devices based on crowd-sourced data. The crowd-sourced data typically includes a list of beacons observed at a particular location along with identification of the particular location as obtained by mobile devices such as laptops, netbooks, and cellular telephones. Existing systems calculate the position of each beacon in the list based on the crowd-sourced data. The beacon positions are then used to estimate the location of devices (e.g., those lacking GPS capability or coverage) that request position information based on an observed list of beacons. The accuracy of these estimated device locations depends in part on the quantity of beacons in the observed list of beacons for which positional information has been previously determined.
To increase the quantity of beacons of known position based on received crowd-sourced data that lacks GPS information, existing systems have attempted to calculate the position of beacons based on signal strength, ambient commercial radio signals, and other broadcast characteristics.